A new study suggests that healthy older men and women can generate just as many new brain cells as younger people, countering the idea that adults are unable to grow new neurons. The research, led by Columbia University neuroscientists, was published today in the journal Cell Stem Cell.
The researchers autopsied hippocampi from 28 previously healthy individuals aged 14-79 who had died suddenly. Prior to autopsy, the researchers confirmed the subjects to not be cognitively impaired and not to have suffered from depression or taken antidepressants, which has been observed to impact production of new brain cells.
The team observed that, even in the oldest individuals, new brain cells are produced. "We found that older people have similar ability to make thousands of hippocampal new neurons from progenitor cells as younger people do," says lead author Maura Boldrini, associate professor of neurobiology at Columbia University. "We also found equivalent volumes of the hippocampus (a brain structure used for emotion and cognition) across ages. Nevertheless, older individuals had less vascularization and maybe less ability of new neurons to make connections."
The researchers theorize that reduced cognitive-emotional resilience in old age may be caused by smaller pools of neural stem cells, decline in vascularization and reduced cell-to-cell connectivity within the hippocampus, rather than a decline in overall neurogenesis.
The team plans to continue to their research on the aging brain with a focus on how neural cell proliferation, maturation and survival are regulated.